JP5737254B2 - Optical communication module - Google Patents

Description

  The present invention relates to an optical communication module that converts an electrical signal into an optical signal and outputs it, or converts an optical signal into an electrical signal and outputs it.

  In optical communication, multi-channel transmission is performed with an increase in communication speed. In an optical communication module for multi-channel transmission, an optical element array in which surface light emitting elements such as VCSELs (Vertical Cavity Surface Emitting LASER) that are easily arrayed or surface light receiving elements such as photodiodes are arranged in an array is used. . The optical element array is placed on a support member (substrate) made of a crystal material such as a metal material, a ceramic material, or silicon.

  In the optical communication module, the optical fiber optically connected to the optical element array is usually arranged in parallel to the surface of the support member in order to facilitate handling. Therefore, in order to optically couple the optical element array that inputs and outputs light perpendicular to the surface of the support member and the optical fiber that inputs and outputs light parallel to the surface of the support member, an optical member ( A lens block or an optical block).

  For example, in Patent Document 1, an optical element having a condensing lens and a reflecting surface for changing an optical path between an optical element array and an optical fiber whose optical path is 90 degrees with respect to the optical element array. The member is arranged. As the optical member, one made of resin or glass is generally used.

  By the way, when assembling the optical communication module, it is necessary to align the optical member and the optical element array.

  As a method for aligning the optical member and the optical element array, a method is known in which the position of the optical member is determined while observing the light intensity transmitted to the optical fiber while the optical element array is in operation. However, in this method, since it is necessary to perform alignment while performing the electrical wiring and performing the measurement while the optical element array is operated, it is very troublesome and has a problem from the viewpoint of mass productivity. .

  As a simpler method for aligning the optical member and the optical element array, a method for performing mechanical alignment without operating the optical element array is known.

  Patent Document 2 proposes a method in which a guide pin is provided on a support member of an optical element array, a hole is provided in an optical member, and the support member of the optical element array is aligned with the optical member as a support member. Yes.

JP 2004-246279 A JP 2006-65358 A

  By the way, the resin used for the optical member has a feature that expansion and contraction due to heat is relatively large as compared with an optical element or the like. Therefore, due to changes in ambient temperature and temperature changes due to heat generation during operation of the optical element array and the semiconductor elements in the module, a difference in size change occurs between the optical element array and the support member and the optical member. There is a problem that misalignment occurs between the optical element array and the optical member that require high alignment accuracy, and the optical communication characteristics deteriorate.

  In the method of Patent Document 2, it is not possible to suppress the occurrence of misalignment between the optical element array and the optical member due to such a temperature change, and furthermore, when the optical member expands with respect to the optical element array and the support member However, there is a possibility that the guide pin and the optical member may be deformed, which is a problem.

  The present invention has been made in view of the above circumstances, and it is possible to mechanically easily align the optical member and the optical element array, and even when the optical member expands / contracts due to heat, the positional deviation is prevented. An object of the present invention is to provide an optical communication module that can be suppressed.

  The present invention has been made to achieve the above object, and includes an optical element array in which light emitting elements or light receiving elements are arranged in an array, a support member on which the optical element array is placed, and the optical element array. A plurality of optical fibers that are optically connected to each other, an optical member that optically couples the optical element array and the optical fiber, a plurality of grooves formed in the support member or the optical member, and the grooves A plurality of protrusions formed on the optical member or the support member so as to correspond to the optical member, and by fitting the groove and the protrusion, the optical member is placed on the support member, An optical communication module configured to position the optical member with respect to the optical element array, wherein the groove is formed to increase in width toward the opening, or the protrusion is at a proximal end. The width of the optical member is increased, and the distance between the support member and the optical member is changed by the interference between the groove and the protrusion when the optical member expands and contracts. A position in the width direction where relative displacement between the groove and the protrusion does not occur when the optical member expands and contracts is formed so as to be positioned on a straight line passing through the center of the optical element array in plan view, The groove and the protrusion are each an optical communication module formed on at least two different straight lines passing through the center of the optical element array in plan view.

  At least one of the groove and the protrusion has a V-shaped cross section in the width direction, and the center position of the V-shaped groove or protrusion in the width direction passes through the center of the optical element array in plan view. You may form so that it may be located on.

  The groove and the protrusion are both formed such that one side surface in the width direction is perpendicular to the surface of the support member, and the side surface is positioned on a straight line passing through the center of the optical element array in plan view. It may be formed as follows.

A length of a bottom surface of the groove may be formed larger than a length of a base end portion of the protrusion.

  The support member may be formed of a silicon substrate, and the groove may be formed in the silicon substrate.

  The optical member has a lens array composed of a plurality of lenses formed at positions facing each light emitting part or light receiving part of the optical element array, and converts the optical axis of light from the optical element array to convert the optical axis. The light may be emitted to each optical fiber, or the optical axis of the light from each optical fiber may be converted and emitted to the optical element array.

  The center of the lens array in plan view and the center of the optical element array in plan view may coincide.

  According to the present invention, optical communication capable of mechanically and simply aligning an optical member and an optical element array and suppressing displacement even when the optical member expands or contracts due to heat. Can provide modules.

It is a figure which shows the optical communication module which concerns on one embodiment of this invention, (a) is the top view which saw through the optical member, (b) is the 1B-1B sectional view, (c) is a groove | channel and protrusion. It is sectional drawing which shows a fitting state. (A)-(d) is a figure explaining a reference position in the present invention. (A) When the center of the optical element array and the lens is a fixed point, (b) When the optical element array and the end of the lens are fixed points, the light emitting portion or the light receiving when the optical member is expanded or contracted It is a figure explaining the position shift of a part and a lens. (A)-(d) is a figure which shows the modification of the optical communication module of FIG. (A)-(d) is a figure which shows the modification of the optical communication module of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1A and 1B are diagrams showing an optical communication module according to the present embodiment, in which FIG. 1A is a top view seen through an optical member, FIG. 1B is a cross-sectional view taken along line 1B-1B, and FIG. It is sectional drawing which shows these fitting states.

  As shown in FIGS. 1A and 1B, the optical communication module 1 includes an optical element array 2, a support member 3, an optical fiber (not shown), and an optical member 4.

  The optical element array 2 includes light emitting elements such as VCSELs or light receiving elements such as photodiodes arranged in an array, and is configured by arranging light emitting parts or light receiving parts 2a in an array on one chip. Although FIG. 1 shows a case where the optical element array 2 has four light emitting units or light receiving units 2a arranged, the number of light emitting units or light receiving units 2a is not limited to this. The distance (pitch) between adjacent light emitting units or light receiving units 2a is, for example, 250 μm.

  The optical element array 2 is placed on the support member 3. The support member 3 is made of a crystal material such as a metal material, a ceramic material, or silicon. When the optical element array 2 is a light emitting element, a driver IC (not shown) for driving the optical element array 2 is mounted on the support member 3. When the optical element array 2 is a light receiving element, an amplifier IC (not shown) that amplifies a signal from the optical element array 2 is mounted on the support member 3. Further, the support member 3 is provided with an electrical connector (not shown) for connecting to an external communication device or the like.

  The optical fiber is optically connected to the optical element array 2, and its front end is arranged in parallel with the surface of the support member 3 in order to facilitate handling.

  The optical member 4 optically couples the optical element array 2 and the optical fiber. In the present embodiment, the optical member 4 has a lens array 4a composed of a plurality of (here, four) lenses formed at positions facing each light emitting part or light receiving part 2a of the optical element array 2, The optical axis of the light from the element array 2 is converted and emitted to each optical fiber, or the optical axis of the light from each optical fiber is converted and emitted to the optical element array 2. The optical member 4 is formed with a V-groove (not shown) for fixing the position of the tip portion of the optical fiber. The optical member 4 is made of resin or glass. The optical member 4 is disposed such that the center of the lens array 4a in plan view coincides with the center of the optical element array 2 in plan view.

  The optical communication module 1 includes a plurality of grooves 5 formed in the support member 3 or the optical member 4 and a plurality of protrusions 6 formed in the optical member 4 or the support member 3 so as to correspond to the grooves 5. The optical member 4 is mounted on the support member 3 and the optical member 4 is positioned with respect to the optical element array 2 by fitting the groove 5 and the protrusion 6.

  In this embodiment, the grooves 5 are formed on the support member 3 and the protrusions 6 are formed on the optical member 4. However, the present invention is not limited thereto, and the protrusions 6 may be formed on the support member 3 and the grooves 5 may be formed on the optical member 4. . When a silicon substrate is used as the support member 3, it is more desirable to form the groove 5 on the support member 3 side because high processing accuracy can be expected by the silicon process.

  The optical element array 2, the support member 3, the distal end portion of the optical fiber, and the optical member 4 are accommodated in a housing (not shown). A transmission side optical communication module 1 using a light emitting element as an optical element array 2 is provided at one end of the optical fiber, and a receiving side light using a light receiving element as the optical element array 2 at the other end of the optical fiber. By providing the communication module 1, an optical active cable is formed. In other words, the optical active cable can be said to use a common optical fiber for the optical communication module 1 on the transmission side and the optical communication module 1 on the reception side.

  In this optical active cable, an electrical signal input from an external communication device or the like is converted into an optical signal in the optical communication module 1 on the transmission side and emitted to an optical fiber. In the optical communication module 1 on the reception side, The optical signal input through the optical fiber is converted into an electric signal and output to another external communication device or the like.

  In the optical communication module 1 according to the present embodiment, the groove 5 is formed so as to increase in width toward the opening, or the protrusion 6 is formed so as to increase in width toward the base end, so that the optical member 4 is formed. The distance between the support member 3 and the optical member 4 is changed by the interference between the groove 5 and the protrusion 6 during the expansion / contraction of the lens.

  In the present embodiment, the groove 5 is formed in the support member 3 and the protrusion 6 is formed in the optical member 4. Therefore, when the temperature is low, the protrusion 6 contracts relative to the groove 5, the interference position (contact position) between the groove 5 and the protrusion 6 approaches the bottom of the groove 5, and the distance between the support member 3 and the optical member 4 increases. Get smaller. Similarly, when the temperature becomes high, the protrusion 6 expands relative to the groove 5, the interference position between the groove 5 and the protrusion 6 moves away from the bottom of the groove 5, and the distance between the support member 3 and the optical member 4 increases. . When the protrusion 6 is formed on the support member 3 and the groove 5 is formed on the optical member 4, conversely, when the temperature is low, the groove 5 contracts relative to the protrusion 6, and the distance between the support member 3 and the optical member 4. Becomes larger. Similarly, when the temperature becomes high, the groove 5 expands relative to the protrusion 6 and the distance between the support member 3 and the optical member 4 becomes small.

  As shown in FIG. 1C, in the present embodiment, the groove 5 is formed so as to increase in width toward the opening, and the protrusion 6 is formed so as to increase in width toward the base end. Either one may be satisfied. In other words, the protrusion 6 may have any shape as long as the groove 5 is formed so that the width increases toward the opening. However, depending on the combination of the shapes of the groove 5 and the protrusion 6, there may be a case where a reference position to be described later does not occur. Further, in this case, the interference position between the groove 5 and the protrusion 6 needs to be in contact with both side surfaces of the groove 5 in a deformation range within an assumed use temperature. The fact that the interference position is not in contact with the side surface of the groove 5 means that the protrusion 6 is removed from the groove 5 or that the protrusion 6 is not restrained in the groove 5 and can move freely in the width direction. This is because both cause positional deviation between the optical element array 2 and the optical member 4.

  For the same reason, when the protrusion 6 is formed so that its width is widened toward the base end and the groove 5 has an arbitrary shape, it is desirable that the groove 5 has a laterally symmetric cross section in the width direction. It is necessary that the interference position between the groove 5 and the protrusion 6 is in contact with both side surfaces of the protrusion 6 within the deformation range within the operating temperature.

  In the present embodiment, the groove 5 and the protrusion 6 have substantially the same V-shaped cross-sectional shape, and the groove 5 and the protrusion 6 are in surface contact. However, if the cross-sectional shapes of the groove 5 and the protrusion 6 are exactly the same, the support member 3 and the optical member 4 come into contact with each other, and the tip of the protrusion 6 comes into contact with the bottom of the groove 5. In this embodiment, the height of the protrusion 6 is made slightly higher than the depth of the groove 5, and the tip of the protrusion 6 is chamfered.

  Further, in the optical communication module 1 according to the present embodiment, the groove 5 and the protrusion 6 are positioned in the width direction (reference) where the relative displacement between the groove 5 and the protrusion 6 does not occur when the optical member 4 is expanded or contracted. Are defined on the straight lines A1 and A2 passing through the center A of the optical element array 2 in plan view (top view).

  Here, the reference position will be described.

  As shown in FIGS. 2A to 2C, when the cross-sectional shapes in the width direction of the groove 5 and the protrusion 6 are substantially the same (however, the height of the protrusion 6 is slightly higher than the depth of the groove 5, Consider a reference position in which the tip of the protrusion 6 is chamfered.

  As shown in FIG. 2A, when the cross-sectional shape in the width direction of the groove 5 and the protrusion 6 is V-shaped (isosceles triangle), when the protrusion 6 is relatively expanded and contracted, No misalignment occurs at the center position in the width direction. Therefore, in this case, the center position in the width direction becomes the reference position. In this embodiment, since the cross-sectional shape in the width direction of the groove 5 and the protrusion 6 is both V-shaped, as shown in FIG. 1A, the groove 5 and the protrusion 6 have a center position in the width direction. In a plan view, it is formed so as to be positioned on the straight lines A1 and A2 passing through the center A of the optical element array 2 (along the straight lines A1 and A2).

  As shown in FIG. 2B, when one side surface in the width direction of the groove 5 and the protrusion 6 is formed perpendicular to the surface of the support member 3, no positional deviation occurs on the side surface. The position of the side surface becomes the reference position. In addition, as shown in FIG. 2C, when the vertex serving as the bottom of the groove 5 is positioned at a position shifted from the center in the width direction of the opening, the position of the vertex becomes the reference position.

  Thus, when the cross-sectional shape of the groove 5 is triangular, the position of the apex that is the bottom of the groove 5 is the reference position, and this reference position is a straight line A1, passing through the center A of the optical element array 2 in plan view. What is necessary is just to form the groove | channel 5 and the processus | protrusion 6 so that it may be located on A2. In addition, as shown in FIG.2 (d), when making the cross-sectional shape of the groove | channel 5 into a trapezoid shape, the position of the vertex which extended the side surface (inclined surface) becomes a reference position.

  Returning to FIG. 1, in the present embodiment, the optical element array 2 is sandwiched on a straight line A1 passing through the center A of the optical element array 2 and along the arrangement direction of the light emitting part or the light receiving part 2a in plan view. Two (two sets) of grooves 5 and protrusions 6 are formed. By the two grooves 5 and the projections 6, positioning in the vertical direction in FIG.

  Here, if the lengths of the grooves 5 and the protrusions 6 are the same, expansion in the left-right direction in FIG. 1A cannot be allowed, causing deformation of the optical member 4 and the support member 3. Therefore, the length of the groove 5 is larger than the length of the protrusion 6, and the protrusion 6 is movable in the length direction of the groove 5.

  Therefore, the two grooves 5 and the protrusions 6 formed on the straight line A1 are positioned in the vertical direction in FIG. 1A, but the horizontal position in FIG. The optical member 4 is allowed to move relative to the support member 3 in the direction along A1.

  Therefore, in the optical communication module 1, a groove 5 and a protrusion 6 are further formed on a straight line A2 that passes through the center A of the optical element array 2 in a plan view and is orthogonal to the straight line A1. The groove 5 and the projection 6 formed on the straight line A2 position the optical member 4 with respect to the support member 3 in the left-right direction in FIG. The length of the groove 5 formed on the straight line A2 is also larger than the length of the protrusion 6, and the movement of the protrusion 6 along the straight line A2 is allowed.

  Here, the grooves 5 and the protrusions 6 are formed on the orthogonal straight lines A1 and A2. However, the present invention is not limited to this, and the reference positions of the grooves 5 and the protrusions 6 pass through the center A of the optical element array 2 in plan view. It suffices to form them so as to be positioned on at least two or more different straight lines (in other words, a straight line extending radially from the center A of the optical element array 2).

  With this configuration, when the optical member 4 expands or contracts due to heat, the position facing the center A of the optical element array 2 of the optical member 4 (that is, the center position of the lens array 4a) is fixed in plan view. As a point, the expansion / contraction deformation is performed radially, and in a cross-sectional view, the distance between the support member 3 and the optical member 4 is maintained while the movement in the width direction of each groove 5 and the protrusion 6 is restricted. To change.

  As shown in FIG. 3A, the center A of the optical element array 2 (the center of the lens array 4a) is used as a fixed point, so that the light emitting section or the light receiving section 2a when the optical member 4 is expanded or contracted by heat. And the positional deviation of the lens 4a can be minimized. On the other hand, for example, as shown in FIG. 3B, when the end of the optical element array 2 (end of the lens array 4a) is a fixed point, the end opposite to the fixed end In this case, the positional deviation between the light emitting unit or light receiving unit 2a and each lens of the lens array 4a becomes large, and the characteristics of optical communication deteriorate.

  As described above, in the optical communication module 1 according to the present embodiment, the groove 5 is formed so that the width increases toward the opening, or the protrusion 6 is formed so that the width increases toward the base end. The distance between the support member 3 and the optical member 4 is changed by the interference between the groove 5 and the protrusion 6 when the optical member 4 is expanded and contracted. The groove 5 and the protrusion 6 are formed when the optical member 4 is expanded and contracted. The position in the width direction (reference position) where no relative displacement occurs between the groove 5 and the protrusion 6 is formed so as to be positioned on the straight lines A1 and A2 passing through the center A of the optical element array 2 in plan view. And the groove | channel 5 and the processus | protrusion 6 are each formed on the at least 2 or more different straight line A1, A2 which passes the center A of the optical element array 2 by planar view.

  With this configuration, the center in the plan view of the optical element array 2 and the center in the plan view of the lens array 4a including four lenses are allowed while allowing expansion and contraction of the optical member 4 with respect to the support member 3 due to heat. Is always maintained at the facing position, and the positional deviation of the optical member 4 with respect to the optical element array 2 can be suppressed, and deterioration of the characteristics of optical communication can be suppressed. In addition, since the optical member 4 can be made of a material such as a resin that is larger in expansion and contraction due to heat than an optical element or the like, it contributes to cost reduction.

  Further, the optical communication module 1 can be mechanically aligned, can be simply aligned without operating the optical element array 2, and is excellent in mass productivity.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the case where the groove 5 and the protrusion 6 are in contact with each other has been described. However, as shown in FIG. 4A, both end portions in the width direction of the protrusion 6 are tapered, As shown in FIG. 4B, the protrusions 6 may be formed in a rectangular parallelepiped shape so that the grooves 5 and the protrusions 6 are in line contact. Moreover, as shown in FIG.4 (c), you may comprise so that the groove | channel 5 and the processus | protrusion 6 may contact at a point, for example by making the processus | protrusion 6 into spherical shape. The plurality of grooves 5 and the protrusions 6 do not have to have the same shape, and various shapes of the grooves 5 and the protrusions 6 can be mixed.

  Moreover, as shown in FIG.4 (d), it is also possible to comprise so that the two protrusions 41 may be fitted to the one groove | channel 5. FIG. In this case, it can be said that the two protrusions 41 correspond to one protrusion 6 because the same effect is obtained even if the space between the two protrusions 41 is filled.

  Moreover, in the said embodiment, although the groove | channel 5 and the processus | protrusion 6 were formed on the straight line A1, A2 along the arrangement direction of the light emission part of the optical element array 2, or the light-receiving part 2a, and the perpendicular direction, the groove | channel 5 and the processus | protrusion 6 Can be appropriately selected as long as the reference position is on a straight line extending radially from the center A of the optical element array 2 in plan view. For example, as shown in FIG. 5A, the groove 5 and the protrusion 6 on the left side of the optical element array 2 in FIG. 1A may be omitted, or as shown in FIG. The grooves 5 and the protrusions 6 may be formed on three straight lines extending from the center A of the array 2 every 120 degrees.

  Further, as shown in FIG. 5 (c), the groove 5 and the protrusion 6 may be further formed on the lower side of the optical element array 2 in FIG. 1 (a) to improve the installation stability of the optical member 4. As shown in FIG. 5D, the relationship between the optical element array 2 and the grooves 5 and the projections 6 in FIG. 5C is rotated (here, the case where the optical element array 2 is rotated by 45 degrees is shown). It is also possible. In FIGS. 5A to 5D, the projections 6 are omitted for simplification of the drawing.

  Furthermore, although the case where the side surface in the width direction of the groove 5 or the protrusion 6 is tapered has been described in the above embodiment, the present invention is not limited thereto, and for example, the side surface in the width direction of the groove 5 or the protrusion 6 is formed in an arc shape. Of course, it is also possible to form it (curved with a predetermined curvature).

  Moreover, in the said embodiment, although the lens was arrange | positioned in the position facing the optical element array 2 of the optical member 4, it is not restricted to this, For example, it opposes an optical element array using the optical member which does not have a lens and a reflecting plate. An incident / exit surface of the optical fiber may be disposed at a position where the optical fiber is located.

DESCRIPTION OF SYMBOLS 1 Optical communication module 2 Optical element array 2a Light emission part or light-receiving part 3 Support member 4 Optical member 4a Lens array 5 Groove 6 Protrusion

Claims (7)

An optical element array in which light emitting elements or light receiving elements are arranged in an array; and
A support member on which the optical element array is placed;
A plurality of optical fibers optically connected to the optical element array;
An optical member for optically coupling the optical element array and the optical fiber;
A plurality of grooves formed in the support member or the optical member;
A plurality of protrusions formed on the optical member or the support member so as to correspond to the groove,
An optical communication module configured to place the optical member on the support member and to position the optical member with respect to the optical element array by fitting the groove and the protrusion,
The groove is formed so as to increase in width toward the opening, or the protrusion is formed so as to increase in width toward the proximal end. The distance between the support member and the optical member is changed,
The groove and the protrusion are positioned on a straight line passing through the center of the optical element array in a plan view so that a relative positional deviation does not occur between the groove and the protrusion when the optical member expands and contracts. Each formed to be located,
And the said groove | channel and the said protrusion are each formed on the at least 2 or more different straight line which passes the center of the said optical element array by planar view. The optical communication module characterized by the above-mentioned. At least one of the groove and the protrusion has a V-shaped cross section in the width direction, and the center position of the V-shaped groove or protrusion in the width direction passes through the center of the optical element array in plan view. The optical communication module according to claim 1, wherein the optical communication module is formed so as to be positioned above. The groove and the protrusion are both formed such that one side surface in the width direction is perpendicular to the surface of the support member, and the side surface is positioned on a straight line passing through the center of the optical element array in plan view. The optical communication module according to claim 1, wherein the optical communication module is formed as described above. The optical communication module according to claim 1, wherein a length of a bottom surface of the groove is formed larger than a length of a base end portion of the protrusion.
The support member is made of a silicon substrate,
The optical communication module according to claim 1, wherein the groove is formed in the silicon substrate. The optical member has a lens array composed of a plurality of lenses formed at positions facing each light emitting part or light receiving part of the optical element array, and converts the optical axis of light from the optical element array to convert the optical axis. The optical communication module according to any one of claims 1 to 5, wherein the optical communication module emits light to each optical fiber or converts the optical axis of light from each optical fiber to emit to the optical element array. The optical communication module according to claim 6, wherein a center of the lens array in a plan view coincides with a center of the optical element array in a plan view.